2561745 has 16 divisors (see below), whose sum is σ = 4161600. Its totient is φ = 1345344.

The previous prime is 2561743. The next prime is 2561749. The reversal of 2561745 is 5471652.

2561745 = T₇₅₀ + T₇₅₁ + ... + T₇₅₈.

2561745 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 2561745 - 2¹ = 2561743 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2561743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 270 + ... + 2279.

It is an arithmetic number, because the mean of its divisors is an integer number (260100).

2^2561745 is an apocalyptic number.

It is an amenable number.

2561745 is a deficient number, since it is larger than the sum of its proper divisors (1599855).

2561745 is a wasteful number, since it uses less digits than its factorization.

2561745 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2624.

The product of its digits is 8400, while the sum is 30.

The square root of 2561745 is about 1600.5452196049. The cubic root of 2561745 is about 136.8291510498.

The spelling of 2561745 in words is "two million, five hundred sixty-one thousand, seven hundred forty-five".